1. Field of the Invention
The invention relates to glazings for an enclosed space and having at least one sheet of glass, including a transmitter and/or a receiver adapted for transmission and/or receipt of electromagnetic radiation traversing the glass, the radiation being in a non-visible portion of the spectrum.
2. Description of the Related Art
It is known to provide signal and data transmission, using electromagnetic radiation in the non-visible portion of the spectrum, for a large variety of applications such as vehicles or buildings. Thus, for example, it is known to use infrared transmitters and receivers to control alarm systems or catches from a distance. In automotive vehicles this enables information to be transmitted relating to traffic situations, the position of the vehicle, communication with toll systems or calculating the separation of one vehicle from others. For buildings, it enables the detection of approaching people.
For such applications it is possible to use microwave or ultraviolet transmitters and receivers. Microwave technology enables many other functions to be carried out, for example by radio telephone in a digital network, digital broadcasting, by satellite or otherwise, as well as vehicle location by satellite remote detection, for example by global position system (GPS).
EP 0 312 788 B1 describes a device having a light transmitter and receiver, both located within a vehicle, the transmitter being arranged so that the light it produces traverses the windscreen and is diffused out of the vehicle while the receiver is disposed so that it can detect and interpret the light transmitted from outside the vehicle and which traverses the windscreen. This device preferable uses infrared radiation.
For such known devices, one uses a glazing which is sufficiently transparent to the electromagnetic radiation to be used. However, it may be undesirable for outside radiation to penetrate to the inside of the space enclosed by this glazing. Such radiation could, for example, prove annoying or harmful to the occupants of the enclosed space. Furthermore, the exraneous radiation passing through the glazing can strike the receiver from different directions, causing an undesirable reduction in the signal/noise ratio.